Terrible Linux performance, great Win32 [SOLVED? - see post]

[Suer7reus]

I am having a terrible time with my Dell XPS (the first one) laptop. It works wonderfully in WinXP, except for the OS, but the Gentoo I've installed on it has never run right. I've set up my share of Gentoo boxes, and all are running smoothly except this. They all compile faster too, even the 4xPIII Xeon 500 Dell server compiling single-threaded. X is terribly sluggish, and my bashmark scores are all hefty negative percentages (vs a K7 1800+). I've taken it to my local LUG, and they agreed unanimously that I have a serious performance problem, but made no progress in correcting it. It takes over an hour to compile a kernel.
I suspect a kernel problem, I guess, but the problem is obvious on all of a) my 2.6.14-nitro2 (or the previous versions) fully preemptable, fully customized kernel, b) my tamer 2.6.14-gentoo-r* kernel, and c) my 2.6.12-gentoo kernel with absolutely nothing but filesystem drivers and IDE/block drivers, no preemption, all default options. I believe bootstrapping from the LiveCD was slow as well (it's been a while), and I have even thrown in a Knoppix (2.6 kernel) CD and compiled and run bashmark with totally fresh toolchain/libs, to no avail. My bashmark (integer) scores range from 200-1000 - they're consistent per the test conditions, but they change depending on whether or not I'm in X, in Knoppix, etc.

Here are my system specs:
P4 Prescott 3.4GHz, Hyperthreading
1Gb PC3200
256Mb Radeon 9800 AGP

For the record, I've tried:
Different kernels and configs, as described above
Every combination of {en|dis}abling HT is BIOS and kernel
Knoppix system
and I know DMA is turned on

What else can I possibly try? Help me! I really don't want to be stuck with this other dysfunctional OS all the time.
Thanks in advance!

[micmac]

Can you post the ouput of 'emerge info'?

[Suer7reus]

Here goes:

[sirdilznik]

Holy USE flag overkill, Batman!!!!!!!!

[Voltago]

Perhaps you should turn off a USE flag or two... Also, look for Inspiron XPS entries in this list:
http://tuxmobil.org/dell.html
they might help you to configure your system.

[hazza]

Just a quick thought: is SpeedStep getting in the way? I have an XPS M140 and it seems to like running at 600MHz unless you ask it nicely

Try the following:

[hazza]

Another thought: you can check CPU frequency without any tools by displaying the contents of /proc/cpuinfo:

[Suer7reus]

Thank you very much for your replies! I shall address them in order:

USE flags - although I have a lot turned on, most of them are local flags, and most of those affect packages I don't even have installed. I have an even more USE-intensive system running on my server, which performs very, very well. I use a lot of the packages the global flags are for, eg apache, mysql, pgsql, etc, but only rarely. I use the machine as an ordinary laptop most of the time, but the kernel has modular support for lots of miscellaneous things so I can turn it into a router in a pinch, for example. I don't run too many services at boot, and top'ping the system shows those I do use are unobtrusive. In any case, the fact that my problem presists even outside the Gentoo system (i.e. the Knoppix I booted and benchmarked under) tells me that USE flags, while they may be a small factor, are not the principal one.
IXPS tuxmobil.org link - Thanks, but I have already done all of the things listed. Gentoo's makes it mighty easy.
I'm fairly familiar with both CPU scaling interfaces - the old ACPI throttling as well as SpeedStep / cpufreq. I am pretty sure that these are not at fault. My CPU is listed in /proc/cpuinfo, cpufreq-info, and the /proc interface to cpufreq as running at full speed. I can change governors and speeds and everything, but I have the system default to the performance governor (i.e. cranked all the way up). I can read the ACPI state from /proc as 0% (throttled down by 0%, i.e. full speed), and I can change it for an extra burst of slowness if I'm so inclined.

Thanks a lot for your input and your time, but my issue remains unresolved.

[falcon_za]

I also suggest you try to go easy on the useflags.

I think that you could go for -O2 instead of -O3. 3 is supposed to make stronger optimization than 2, but it also usualy results in larger files. On a laptop, which has limited hard drive performance, and possibly limited caches size and memory bandwidth, I think It might actualy result in slower performance. As for as the -funroll-loops, the situation might have changed without my knowing, but it used to be a broken flag, best avoided.

All that said, if other distro have proven sluggish too, it is likely unrelated to the way you configured your box, but if I were you, I'd still try to go with a slightly more conventional config.
_________________
Why the hell am I in Asia? Don't remember. But I am still glad i am here.

You're glad someone did it for you, so help noobs.

[hazza]

[Pse]

What kind of hardware is there in your machine? (apart from your graphics card, CPU and memories?)

[saber850]

One significant performance problem I've had was caused by no DMA on the hard disk.
Aside from DMA, there's a slew of other params that affect your HD performance.
Use hdparm to check your config and tweak as necessary.

[Suer7reus]

Thank you all again for your replies!
Prepare yourselves for the mother of all posts, heh.
I shall address them in order again:
USE flags - not to be changed in pursuit of a solution to this problem as the problem presists even in non-Gentoo Linux systems (i.e. Knoppix).
CFLAGS - also should not affect the Knoppix system. My laptop is designed to be a gaming platform and therefore has a 7200RPM UDMA5 disk drive as well as plenty of cache and memory bandwidth. Therefore, I don't think -O* should make a big difference, and I'm certain it should not make the difference the below bashmark results demonstrate. -funroll-loops works just fine on all my other boxes, and has for quite some time, and as such I am inclined to trust it.
Regarding the above, I have considered changing some flags, but intend to deal with the matter once this problem is resolved and the machine can [re]compile code fast enough to be worth my bother.
Obscure hardware - I actually have not checked my hardware out much at all - upon install it sounded simple enough and appeared to be well-supported in the kernel, but I can't help but think you're barking up the right tree now in light of my troubles.

Here's dmesg right after boot of my absolute bare-bones compiled-just-for-this-test 2.6.12 kernel:

[hansmaa]

I don't know if this might help, but have you tried passing the 'irqpoll' option to the kernel from the bootloader??

You might have some none-fatal irq conflicts that slows your system down...

[MaGuS]

Hi,

did you tried to turn off preemptable? On one box i got the same problem, after turning off preemptable the system is running much better!

Best regards,
Magnus
_________________
Running Gentoo as:
htpc with vdr and many plugins (DVB-S and DVB-T) on an AMD Athlon(tm) XP 2600+
router with shorewall on an apple mac mini
web and e-mail server on a dell (root server)

[cyanide_nfs]

well, i didnt mean to rub it in or anything, but your bashmark results seem kinda low...

heres my results with a a64 2800+ with 512mb ddr400 ram:

[Suer7reus]

Thank you again!
irqpoll - I shall try this as soon as I return to the computer this afternoon - this is the kind of suggestion I was hoping for. Thank you!
preemptable - I have tried both preemptable and non-preemptable kernels. Neither performs correctly. Good suggestion though; preemption seems like the kind of change that could so affect performance in certain circumstances, just not mine apparently.
bashmark - Agreed! I wonder if my preposterously low floating point scores are at all indicative of the true cause of my problem. What that cause might be, I don't know, I'm just thinking out loud.
Thanks again; update tonight!

[hansmaa]

Also try to add 'pci=usepirqmask' option to the kernel from the bootloader. Your dmesg complains about it.

Also, dmesg shows some unwillingness to lock on to what kind of cpu you have. (At least to me, being an AMD user)
Have you compiled your kernel for a different cpu than you are running it on??

[linuxtuxhellsinki]

I'll give you this from my ThinkPad, just for fun

[GNUtoo]

[Felixlein]

Why is nearly everybody complaining about use-flags?
I dont think they have anything to do with the poor guys
about-zero-floating-point-performance...

[Felixlein]

Hmm,I also have this bad fpu-performance,listening to bashmark;
didn't recognize it until now...

samuelcolt felixlein # bashmark
#######################################################
: T E S T : :S C O R E : : R A T I O:
:-----------------------------------------------------:
:Cpu, Integer : : 914: : -15%:
:Cpu, Floating point : : 21: : -97%:
: : : : : :
:Memory r/w (cached) : : 645: : -46%:
:Memory de-/alloc : : 233: : -64%:
: : : : : :
:Multithreading : : 686: : -72%:
#######################################################
: S Y S T E M I N F O :
-------------------------------------------------------
2x Intel(R) Pentium(R) 4 3065.563MHz, L2 512KB
Linux 2.6.15-gentoo
GCC 4.1.0-beta20060106
88KB binary size
#######################################################

[GNUtoo]

is the cpu trotelling???
cat /proc/acpi/processor/CPU0/throttling
if it's not to 00 it's trotelling
check it when you do your benchhmark

mabe also try remplacing your root by a stage3 and run the test for showing that it's not the use flags (how this could be possible...it just make run the program heavyer...not the system so slow)

#######################################################
: T E S T : :S C O R E : : R A T I O:
:-----------------------------------------------------:
:Cpu, Integer : : 420: : -61%:
:Cpu, Floating point : : 33: : -96%:
: : : : : :
:Memory r/w (cached) : : 920: : -24%:
:Memory de-/alloc : : 118: : -82%:
: : : : : :
:Multithreading : : 397: : -84%:
#######################################################
: S Y S T E M I N F O :
-------------------------------------------------------
1x Pentium III (Coppermine) 697.946MHz, L2 256KB
Linux 2.6.14-gentoo-r2_dell_inspiron2500
GCC 3.3.5-20050130
100KB binary size

while running some kde,konqueror(a lot of instances),xconfig,firefox(a lot of tabs),xterm(a lot of instances)

try it under windows
what is the result?

[cyanide_nfs]

is it just me or are the pentiums really bad in the benchmarks ?

[GNUtoo]

it's said on the faq that the "intel processors" are bad at this benchmark